We've always had positive results with
Preferred Vacation Rentals Inc. (used to be Preferred Properties)
They advertise all over the place, have linens available, and have gone as far as purchase a new fridge (at a very good price) when our's broke down. When we return in the fall our place is as clean as we leave it.
If this is your first time to rent, you might want go a little lower than the agency suggests, and if you make your place inviting to your guests, they will want to return next year.
Good luck, Chris